• Smart Structures and Systems
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• 제3권4호
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• pp.423-437
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• 2007

The empirical mode decomposition (EMD) method is well-known for its ability to decompose a multi-component signal into a set of intrinsic mode functions (IMFs). The method uses a sifting process in which local extrema of a signal are identified and followed by a spline fitting approximation for decomposition. This method provides an effective and robust approach for decomposing nonlinear and non-stationary signals. On the other hand, the IMF components do not automatically guarantee a well-defined physical meaning hence it is necessary to validate the IMF components carefully prior to any further processing and interpretation. In this paper, an attempt to use the EMD method to identify properties of nonlinear elastic multi-degree-of-freedom structures is explored. It is first shown that the IMF components of the displacement and velocity responses of a nonlinear elastic structure are numerically close to the nonlinear normal mode (NNM) responses obtained from two-dimensional invariant manifolds. The IMF components can then be used in the context of the NNM method to estimate the properties of the nonlinear elastic structure. A two-degree-of-freedom shear-beam building model is used as an example to illustrate the proposed technique. Numerical results show that combining the EMD and the NNM method provides a possible means for obtaining nonlinear properties in a structure.

• The Korean Journal of Pain
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• 제1권2호
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• pp.199-202
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• 1988

Secure fixation is essential for continous epidural catheterization on a long-term-basis. Adhesive tape or surgical knots were commonly used for those patients, but the surgical knot method has a tendency to cause strangulation of catheter. Another invasive technique, subcutaneous tissue tunnelling is more safe than other methods but requires sophisticated technique and time. We employed a simple device using a blood transfusion set for patients who have epidural catheters placed safely un their backs. In 120 patients treated for postoperative and chronic pain by means of this technique, the results were as follows: 1) Five of 120 patients (4.2%) developed backache and pruritus, but there were no instances of respiratory depression, local infection and headache. 2) Nine of 120 patients (7.5%) failed booster-injections, but two cases were due to be non-technical errors. 3) The duration of fixation was 1~3 days in most cases (85%), the longest being for 21 days.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2555-2575
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• 2017

This paper presents a dual exposure fusion method for image enhancement. Images taken with a short exposure time usually contain a sharp structure, but they are dark and are prone to be contaminated by noise. In contrast, long-exposure images are bright and noise-free, but usually suffer from blurring artifacts. Thus, we fuse the dual exposures to generate an enhanced image that is well-exposed, noise-free, and blur-free. To this end, we present a new scale-space patch-match method to find correspondences between the short and long exposures so that proper color components can be combined within a proposed dual non-local (DNL) means framework. We also present a residual filtering method that eliminates the structure component in the estimated noise image in order to obtain a sharper and further enhanced image. To this end, the entropy is utilized to determine the proper size of the filtering window. Experimental results show that our method generates ghost-free, noise-free, and blur-free enhanced images from the short and long exposure pairs for various dynamic scenes.

• 한국IT서비스학회지
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• 제5권3호
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• pp.173-186
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• 2006

The local public organizations, to secure the Confidentiality, Integrity, Authentication and Non-Repudiation of cyber administrative environment is giving it a try to consolidate the official documents among them by standardizing all the documents into XML formats together with the establishment of the GPKI(Government Public Key Infrastructure). The Authentication System based on the PKI(Public Key Infrastructure) used by the GPKI, however, provides only the simple User Authentication and thus it results in the difficulty in managing the position, task, role information of various users required under the applied task environment of public organizations. It also has a limitation of not supporting the detailed access control with respect to the XML-based public documents.In order to solve these issues, this study has analyzed the security problems of Authentication and access control system used by the public organizations and has drawn the means of troubleshoot based on the analysis results through the scenario and most importantly it suggests the access control model applied with PMI and SAML and XACML to solve the located problem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3620-3637
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• 2019

Since the birth of Synthetic Aperture Radar (SAR), it has been widely used in the military field and so on. However, the existence of speckle noise makes a good deal inconvenience for the subsequent image processing. The continuous development of sparse representation (SR) opens a new field for the speckle suppressing of SAR image. Although the SR de-noising may be effective, the over-smooth phenomenon still has bad influence on the integrity of the image information. In this paper, one novel SAR image de-noising method based on residual image fusion and sparse representation is proposed. Firstly we can get the similar block groups by the non-local similar block matching method (NLS-BM). Then SR de-noising based on the adaptive K-means singular value decomposition (K-SVD) is adopted to obtain the initial de-noised image and residual image. The residual image is processed by Shearlet transform (ST), and the corresponding de-noising methods are applied on it. Finally, in ST domain the low-frequency and high-frequency components of the initial de-noised and residual image are fused respectively by relevant fusion rules. The final de-noised image can be recovered by inverse ST. Experimental results show the proposed method can not only suppress the speckle effectively, but also save more details and other useful information of the original SAR image, which could provide more authentic and credible records for the follow-up image processing.

• 산업기술연구
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• 제43권1호
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• pp.7-13
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• 2023

Nowadays, traffic congestion is emerging as a major problem due to the rapid population growth and the increase in automobiles. The train is a convenient means of transportation that can efficiently solve these problems. Trains have been developed in line with human aspirations for a long time, but research on safety is still insufficient. This study aims to check safety by conducting static tests and fatigue tests on bogie frames, and to help develop bogie frames in the future. For the static test, a strain gauge was attached to the point where the local stress concentration was expected beforehand, and the result value was derived, compared with existing theories, and expressed as a Goodman diagram. In the fatigue test, a total of 10 million loads were applied over three stages, and no cracks appeared in the non-destructive test conducted after each stage. Both tests were conducted according to the strict test method of the bogie frame presented by the UIC Code. It satisfied both fatigue life and strength evaluation criteria and was judged to be a bogie frame usable for safe train production.

• 전기학회논문지
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• 제60권3호
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• pp.639-647
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• 2011

In this paper, we introduce a design methodology of data-centroid Radial Basis Function neural networks with extended polynomial function. The two underlying design mechanisms of such networks involve K-means clustering method and Particle Swarm Optimization(PSO). The proposed algorithm is based on K-means clustering method for efficient processing of data and the optimization of model was carried out using PSO. In this paper, as the connection weight of RBF neural networks, we are able to use four types of polynomials such as simplified, linear, quadratic, and modified quadratic. Using K-means clustering, the center values of Gaussian function as activation function are selected. And the PSO-based RBF neural networks results in a structurally optimized structure and comes with a higher level of flexibility than the one encountered in the conventional RBF neural networks. The PSO-based design procedure being applied at each node of RBF neural networks leads to the selection of preferred parameters with specific local characteristics (such as the number of input variables, a specific set of input variables, and the distribution constant value in activation function) available within the RBF neural networks. To evaluate the performance of the proposed data-centroid RBF neural network with extended polynomial function, the model is experimented with using the nonlinear process data(2-Dimensional synthetic data and Mackey-Glass time series process data) and the Machine Learning dataset(NOx emission process data in gas turbine plant, Automobile Miles per Gallon(MPG) data, and Boston housing data). For the characteristic analysis of the given entire dataset with non-linearity as well as the efficient construction and evaluation of the dynamic network model, the partition of the given entire dataset distinguishes between two cases of Division I(training dataset and testing dataset) and Division II(training dataset, validation dataset, and testing dataset). A comparative analysis shows that the proposed RBF neural networks produces model with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.

• 한국산림과학회지
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• 제105권3호
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• pp.366-376
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• 2016

인도네시아의 산림 파트너십 제도는 지방 산림관리소(KPH)를 포함한 허가 권리 보유자와 지역주민 간 계약체결을 통해 산림을 관리하고 수익을 배분하는 제도이다. 본 논문의 목적은 산림 파트너십 제도를 도입한 초기에 인도네시아의 롬복 산림 파트너십에 참여한 지역주민의 인식을 바탕으로 본 제도가 직면한 도전 과제를 도출하는 데 있다. 이런 목적을 달성하기 위하여 산림관리소(KPH)와 지역주민이 체결한 인도네시아 최초의 롬복 산림 파트너십에 참여한 지역주민의 인식을 조사하였다. 롬복의 지역주민은 산림 파트너십에 대한 정보를 전적으로 KPH와 NGO로부터 획득하고 있다. 롬복의 지역주민은 소득 증진을 기대하고 산림 파트너십에 참여하였으며 목재 생산을 가장 중요하고 성공 가능성이 높은 소득증진 사업으로 인식하였다. 이런 측면에서 관할 지역의 특별산림을 지역주민이 이용할 수 있도록 허가해 주고 이로부터 발생하는 수익을 지역주민과 나누고자 하는 KPH의 리더십은 산림 파트너십 성공의 핵심 요소이다. 또한 지역주민의 소득 증진 사업을 개발하고 이행할 수 있도록 KPH의 능력을 배양하는 것은 산림 파트너십이 당면한 도전 과제이다. 롬복 산림 파트너십에 참여한 지역주민은 수익배분 비율이 매우 높음에도 불구하고 만족도는 평균에 그쳤다. 또한 조합은 조합원에게 산림 면적 및 위치를 할당하는 민감한 사안을 다루어야 한다. 이런 측면에서 지역주민 조합이 형평성과 투명성의 원칙을 지키며 전 조합원의 참여와 합의를 이끌어내는 것은 산림 파트너십의 도전 과제가 될 것이다.

• 한국경제지리학회지
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• 제20권1호
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• pp.105-120
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• 2017

충주 기업도시는 2005년에 시범사업 지역으로 선정되어 2020년 완공을 목표로 하고 있다. 본 연구의 목적은 선진국 기업도시의 성공요인을 토대로 충주 기업도시의 발전 전략 및 활성화 방안을 제시하는데 있다. 충주 기업도시는 충청북도의 신성장 동력산업인 첨단지식 산업 중심 클러스터와 주변의 뛰어난 자연 환경을 배경으로 친환경 웰빙 자족도시로 성장시킬 예정이다. 충주 기업도시가 성공하기 위해서는 기업, 대학, 지자체, 정부 등 개발 주체 사이의 협력이 중요하고, 선도기업과 연구 기관을 유치해야 하며, 비영리 전담기구를 설치해야 한다. 충주 기업도시의 성공적 개발은 수도권 과밀화와 국토 불균형을 해결하는 지역균형개발 정책의 성공을 의미한다.

• 한국물환경학회지
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• 제20권5호
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• pp.397-408
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• 2004

Due to the growing impact of non-point source pollution and limitation of water treatment technology, a new policy of water quality management, called a source protection, is now becoming more important in drinking water supply. The source protection means that the public agency purchases the pollution sensitive area, such as riparian zone, and prohibit locations of point and non-point sources. Many studies have reported that this new policy is more economical in drinking water supply than the conventional one. However, it is very difficult to determine location and size of the pollution sensitive zone in the watershed. In this paper, we presented the scientific criteria for the priority of the pollution sensitive zone, along with a case study of the upstream watershed of the Paldang Reservoir, Han River. This study includes applications of the analytical hierarchy process(AHP) and a watershed-based land prioritization(WLP) model. After major criteria affecting water quality were selected, the AHP and geographic analysis were performed. The WLP model allowed us to include both quantity and quality criteria, using AHP as the multi-criteria method in making decision and reflecting local characteristics and various needs. By adding a travel-time function, which represents the prototype effectively, the results secured adaptability and scientific objectivity as well. As such, the WLP model appeared to provide reasonable criteria in determining the prioritization of land acquisition. If the tested data are used with a validated travel-time and AHP method is applied after further discussion among experts in such field, highly reliable results can be obtained.